Spinning plate

ABSTRACT

The invention relates to a spinning plate for the production of melt-spun fibers in order to produce geotextiles.

The invention relates to a spinneret plate for producing melt-spunfibers for the production of geotextiles

Geotextiles are employed in many fields of technology, in particular forreinforcing embankments, slopes, as a base for concrete or asphaltsurfaces, such as streets, airports, roads, bridges and the like, andspecifically for new constructions as well as for redevelopments.Special requirements are made of the stability, strength and the waterpermeability of the geotextiles depending on the specific field ofapplication.

Depending on the required property, until now fibers and filaments ofdifferent defined textures have been produced and solidified in theproduction of geotextiles. The finer the fibers or filaments, thestronger, and more stable is the geotextile after the solidification;the coarser the fibers or filaments, the higher is the waterpermeability of the geotextile. Optionally separately produced finerfibers are added before the solidification of a geotextile in order toattain the corresponding strength and stability.

The invention addresses the problem of providing a method and a devicefor the production of geotextiles comprised of fibers or filaments ofdifferent textures, in which the mixing or the adjusting of the fibermixture does not laboriously take place after the production of thefibers and filaments, but rather already during the production of thefibers or filaments.

Subject matter of the invention is therefore a method for the productionof geotextiles, characterized in that the production of continuousfibers of different texture takes place in one spinning process, wherebythe adjustment of the ratio of fibers of finer and coarser texture isdefined and, in the subsequent mechanical and/or hydraulicsolidification, a geotextile with defined properties is produced.

A further subject matter of the invention is a spinneret plate for theproduction of melt-spun continuous fibers for geotextiles, characterizedin that the spinneret plate has bores of different diameters for theproduction of fibers of different texture in one spinning process.

Through the proportion of finer fibers, the desired stability andstrength of the finished geotextile can be adjusted. The proportion ofcoarser fibers determines the hydraulic properties of the finishedgeotextile, for example the water permeability in the nonwoven fabricplane or normal to the nonwoven fabric plane.

The higher the proportion of fine fibers, the stronger and more stableis the geotextile subsequently produced through mechanical and/orhydraulic solidification. The higher the proportion of coarser fibers,the higher is the water permeability of the geotextile after themechanical and/or hydraulic solidification.

Possible starting materials for the fine as well as also for the coarserfibers are, for example, synthetic materials, such as polypropylene,polyethylene, polyamide or polyester.

By fine fibers, which serve for the mechanical and/or hydraulicsolidification of the geotextile, are understood fibers having a textureof 1-10 dtex, preferably 1-7 dtex. As a function of the selected textureof the finer fibers, the coarser fibers have a texture of 6-30 dtex,preferably 7-27 dtex.

The textures of the fiber types preferably differ by a factor of 3 to20, especially preferred by a factor of 4 to 6.

Depending on the desired properties, in particular on the desiredcombination of strength, stability and water permeability, and as afunction of the selected textures, the proportion of fine fibers in thefinished geotextile can be 20-95%, preferably 30-90%.

However, it is also possible to use more than two fibers of differenttexture. In this case, three or more fibers of different texture areutilized for the production of the geotextile, the selection of thetextures, again, being dependent on the desired properties of thefinished geotextile.

The fibers of different texture are produced in one spinning processutilizing the spinneret plate according to the invention. The fibers aresubsequently laid down in the conventional manner and mechanicallyand/or hydraulically, chemically and/or thermally solidified.

For the production of a defined mixture of fibers or filaments ofdifferent texture, a spinneret plate with differently defined bores isutilized and thereby the mixing ratio of fibers and their texture isalready defined during the production of the fibers.

This spinneret plate according to the invention has bores with differentcapillary diameters for the simultaneous production of continuous fibersof different texture.

The capillary diameters of the bores are so dimensioned that the fibersof different texture can be produced simultaneously in the desiredratio.

The bores can therein be distributed at regular intervals as well asalso randomly.

Depending on the desired cross section of the fiber, the capillary boresmay have suitable shapes (trilobal, octalobal, star-shaped, hollow,triangular, triangular hollow, etc.) wherein the cross sections of thefine and the coarser fibers, or optionally of further utilized fibers,may also be different.

EXAMPLE 1

Standard Geotextile Starting material (granulate) PolypropyleneProportion of fine filaments, % 100 Filament titer, dtex 4 Proportion ofcoarse filaments, % 0 Filament titer, dtex — Weight/unit area, g/m² 250Wide width tensile strength EN ISO 10319, kN/m Longitudinal 19.1Transverse 19.4 Water permeability in the geotextile plane EN ISO 129583.0 · 10⁻³ 20 kPa, i = 1, [l/m/s] Water permeability normal to the planeEN ISO 11058 5.1 · 10⁻² VI_(H50) [m/s]

EXAMPLE 2

Starting material (granulate) Polypropylene Proportion of finefilaments, % 90 Filament titer, dtex 4 Proportion of coarse filaments, %10 Filament titer, dtex 18 Weight/unit area, g/m² 250 Wide width tensilestrength EN ISO 10319, kN/m Longitudinal 18.8 Transverse 19.0 Waterpermeability in the geotextile plane EN ISO 12958 8.2 · 10⁻³ 20 kPa, i =1, [l/ms/s] Water permeability normal to the plane EN ISO 11058 8.4 ·10⁻² VI_(H50) [m/s]

EXAMPLE 3

Starting material (granulate) Polypropylene Proportion of finefilaments, % 70 Filament titer, dtex 3 Proportion of coarse filaments, %30 Filament titer, dtex 15 Weight/unit area, g/m² 250 Wide width tensilestrength EN ISO 10319, kN/m Longitudinal 18.5 Transverse 18.7 Waterpermeability in the geotextile plane EN ISO 12958 1.1 · 10⁻² 20 kPa, i =1, [l/ms/s] Water permeability normal to the plane EN ISO 11058 1.2 ·10⁻¹ VI_(H50) [m/s]

1. Method for the production of geotextiles, wherein the production ofthe continuous fibers of different texture takes place in one spinningprocess, wherein the adjustment of the ratio of fibers of finer andcoarser texture is defined and, in the subsequent mechanical and/orhydraulic solidification, a geotextile with defined properties isproduced.
 2. Method as claimed in claim 1, wherein the finer fibers havea texture of 1-10 dtex.
 3. Method as claimed in claim 1, wherein thecoarser fibers have a texture of 5-30 dtex.
 4. Method as claimed inclaim 1, wherein the proportion of finer fibers is 20-95%.
 5. Method asclaimed in claim 1, wherein two or more fibers of different texture areproduced in one spinning process.
 6. Spinneret plate for the productionof melt-spun continuous fibers for geotextiles, wherein the spinneretplate has bores of different diameters for producing fibers of differenttexture in one spinning process.
 7. Spinneret plate as claimed in claim6, wherein the bores have identical or different non-round crosssectional shapes.
 8. Geotextile produced utilizing a method claimed inclaim 1.